constant call no messages left

Annoying scum calls my Google Voice number every few days and leaves a 3-second blank message.  I don't answer because I don't recognize the number as anyone I've given that number to, and if they were legitimate they'd leave a message. So I will assume they have criminal intent.

Don't answer, they're no one important

Called about my inquiry of a reverse mortgage..  I never made an inquiry.  Told him he was an A hole and he just kept rattling on.. Called twice within 2 minutes